/Engine/Plugins/Editor/ObjectMixer/ObjectMixer/Source/ObjectMixer/Public/Views/List/SObjectMixerEditorList.h
BeginSSceneOutlinerInterface
virtual void CustomAddToToolbar ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< class [SHorizontalBox](API\Runtime\SlateCore\Widgets\SHorizontalBox) > Toolbar )